DEVICE FOR CLEARING BOTTOM HOLE Russian patent published in 1997 - IPC

FIELD: oil and gas industry. SUBSTANCE: device is intended for use in development, routine and overhaul repairs of oil, gas and injection wells for clearing bottom hole from sand plug. Device has hollow body with guide bush in its upper part. Installed in lower end of body is receiving valve. Connected to lower open end of pump-compressor tube string is plunger. Side walls of plunger lower part inserted into hollow body have radial through-holes. Installed between upper end of hollow body and circular shoulder made in plunger is spring which is in prestressed condition. Hollow body in its lower part above receiving valve is made splittable and is inserted into receiving valve body with possibility for axial displacement. Located on outer surface of hollow body between thrust shoulder and receiving valve body is packer sealing resting against bottom hole. When receiving valve comes in contact with bottom hole, plunger moves down. Under weight of pump-compressor tube string, packer sealing is tightly pressed against production string, higher pressure is created in under-packer space, and liquid together with sand, sludge fills inner space of device and pump-compressor tube string at high velocity. EFFECT: high efficiency. 1 dwg